Floor sanding edger



Aug. 28, 1951 w, P, HlLGER 2,565,658

FLOOR $ANDING EDGER Filed May 25, 1946 5 SheetsSheet l IN VEN TOR.

Aug. 28, 1951 w. P. HILGER FLOOR SANDING EDGER 6 Sheets-Sheet 2 Filed May 23, 1946 INVENTOR WM F. H1

ATTORN Y w. P. HILGER FLOOR SANDING EDGER Aug. 28, 1951 5 Sheets-$heet 4 Filed May 25, 1946 6 a 5 2 .0 MG 4. Y\ \V 1 WUU E .1 G1. I i r F M 5 mm a 5 L} m 5 L m rm h a I: O6 w; \4 6 \4 5 H \4 O 4% N 2 a (\Al 5.

4 Am 5 Z w "on:

irony :Aug. 28, 1951 w. P. HILGER FLOOR SANDING EDGER 5 Sheets-Sheet 5 Filed May 25, 1946 INVENTOR. Wmmam E HILL-ER W 4 TTORNEY.

Aug. 28, 1951 w. P. HILGER FLOOR SANDING EDGER Filed May 23, 1946 6 Sheets-Sheet 6 INVENTOR. WILLIHM E HILEBR BY I ' ATTORNEY;

Patented Aug. 28, 1951 UNITED PATENT :F-FalxC-E liFI'iOLDRiYSANDINGiEDGER "Wi'lliamTPLHilger,"St.,Cloud, Minn. .-.Application May 23;1946,TSerial' No. 671,7-52

ZJClaims. 1

. My invention relates ,to afioor1sandil'ggzed ltr. andhas for .its object to provide an-eedgerzconstruction employingia novel fiexiblediskof-reinforced. rubber which enables theledgento operate fully up to the baseboard molding, at the room corners and elsewhere, andrwhichisgso; arranged and controlled that neither floor gouging ;or overloadin the motorpcan take place, together with novel features which; add-greatly to,the-usefulness andefiective operation of-ga fioor sanding edger.

As is well known, and; particularly applicable to better ,types of floors, such as good hardwood floors, such floors in use, either from wearing or. from other.c.auses, .become uneven and show wear inspots and; in other ways; develop: surtace defects which takeaway from .the beauty and effectiveness .of the. fioor. :To; remedy these .jdefects what is'known as floor sanding has been quite generally practiced. .This consistswfzthe application to the surfaceof the-floor of sanding paper usua'llyheld uponarotatingddrum which may .be operated '.to remove .and smooth and polish enough of the floor surface ,toeliminate the defects and substantially renew .the ifioor.

Although edgers made by me are so constructed that they willoperate underneathlowobbjects, such as-"radiators, such "floor sanders and the rotatin drums thereonmay not always operate clear up to the baseboard or the molding at .the bottom of-the'baseboard, and cannot do so. aidjacent the-rooms corners, so "when the. general sanding operation *has been completedthere are margins of unsanded floor adjacent -thebaseboard and its-moldings. -It -is-'the*f-nnction of floor sandingedgers, so called, to-elfecta sanding operation. on: this 'unsanded margin-to' make it :uniformuwith the theretofore sanded portions of;the'main-fioor.

.=Different types of floor sanding edgers have been-devised having the purpose.- f bringing the operative part of the floor sanding member diofzthe diskqitallowssexcessiveforceztozlcetapplie'dto the .diskaand r to the :sanding ioperationcwhich Producestwo serious :defects. in; operation. LOne ofcth'ese: is that .the jfloor surface :being.;sanded byirthe :edger is scored and.gouged:and swirlmarked. .The :other is-thatthe operator :may use eexcessive pressure on. the sanding.- disk,=.too great for the motor GI'IIDIOYEGyWhiCh, inzthis type ;;of edger, 11S for'that reason frequently caused torburn'out.

Another serious difficulty: with e'dgers,:,:as:-heretofore.:built;an'd operated, 'hashbeeniinability to remove and collect the dust :generatedeby "the sanding. disk and to convey -.it to the: dust bag in such :a manner-.that. it cani-not-get inton-the bearings of eitherithec sanding: disk"orrthe-xmotor which furnishes the power therefor. This dust includes not only wood particles '5 from. the' 'fioor but hard particles fromithesand paper; and has thezefiect of: rapidly wearing :out bearingsif it. is permittedwto'reach :andzgo into: them.

.-; Still-another difficulty has been found in the fact that not only has no perfect -dust collecting job been eflected, but that neitherby the dust col1ecting::means,-nor by any-:other means, has there :been entirely satisfactory and effective means. of cooling the motor; something very important in sanding machines'sincethe motor-is loaded and tends to :heat unless the' heatis -in a-proper manner removed.

II" have discovered simple and effective means to remedy zall-these defects an'd d-i-fiiculties. The means discovered for the sanding operationitself *comprisesn flexible diskso shaped/mounted and rotated :that needed high speed of rotation of the disk will through centrifugal force' bring the operative. surface of the disk into sanding contactavith the floor over -3, substantiah area with suificientmressure exercised by a uniform yielding .centrifugal action to produce a most efiective, smooth sanding operation, I and-yet so it .is impossible-to exert-enough=pressure-on the disk and floor to'iniure the'floor by scoring or gouging ,or swirlemarking, or to overload and burn out the light type of motor "necessary to beemployed. in this-kind of structure.

Also ithis' disk, :=preterably dlsh-shaped, either concave or conveX to the floor, I is so mounted-in relation .to ::the housing for the drivin --means in'gthezmotor and in relation to the'dust' removal means that allidust' is: picked-:upwheregenerated and ,iszcarriedoutof the machine: along: passages whichzva-idi*in :cooling the motor, and-which are so related to the motor bearings and the-disk bearing :tthat .such :dust =2-is :effectively excluded therefrom.

with a very substantial area of the front part 7 of the disk in sanding contact therewith.

It is a further object of my invention to pro'-.

vide means such that when sanding contact of the disk has been established a suflicient pressure for most efiicient sanding operation may be secured by centrifugal action, together with means preventing said pressure ever becoming excessive and thus preventing scoring the floor or overloading and burning out the motor.

It is a further object of my invention to provide a casing for the sanding edger which is mounted and rocks upon a set of rollers, said casing having a portion forwardly extended and formed With an air-tight housing for the drive means for the disk, said casing being adapted to be tipped downwardly when in operation, whereby the disk carried thereby will first contact the floor at a point near its edge and thereafter will be slowed by friction with the floor so that a considerable area of the front of the disk will engage the floor up to the bottom edge of the base molding, together with means on the casing to prevent excessive pressure of the disk against the floor.

It is a further object of my invention to provide .a highly novel sanding disk formed of rubher with nonstretchable reinforcing material within the body of the disk, said disk being dishshaped, either concave or convex, preferably concave, to the floor.

It is a further object of my invention to provide in said casing an air-tight housing for the driving means for the disk to eliminate possibility of sander dust contacting any of the drive means and bearings for rotating the disk.

It is a further object of my invention to provide means for drawing away the sander dust formed by the sanding edger operation and conducting it to the dust bag which shall convey it in such manner that the motor casing will be partly cooled and yet none of the air carrying said dust or any of the dust can reach the motor chamber or the motor bearings.

It is a further object of my invention to provide an arrangement of the motor in the casing in combination with a blower so that outside air will be drawn into and forced through the motor chamber and be discharged from the chamber and casing back outside the machine, and the motor thus be'additionally cooled.

The full objects and advantages of my invention will appear in connection with the detailed description thereof given in the appended specification, and the advantageous results above noted which come from the use of the invention will be particularly pointed out in the claims.

Fig. 1 is a top plan view of the entire machine with the dust collecting bag omitted.

Fig. 2 is a longitudinal sectional elevation view of the machine taken along the top center line thereof.

Fig. 3 is a sectional plan View of the machine taken on line 33 of Fig. 2. I

Fig. 4 is a bottom plan view of the machine viewed upwardly with the sanding disk omitted.

Fig. 5 is a transverse sectional view taken through the bottom part of the machine on line 5-5 of Fig. 1 in inverted or machine-supporting position.

Fig. 6 is a front elevation of the machine as seen from the right hand side of Fig. 5.

Fig. 7 is an enlarged side elevational view of the front end of the machine from the supporting wheels forward, showing the disk in fully operative position when the frame has been pressed down so the front end of it is resting on the floor.

Fig. 8 is a bottom plan view of the sanding edger disk on a reduced scale viewed from below showing in the shaded area the part of the disk which first contacts the surface while running at an initial high speed.

Fig. 9 is a similar view on a similarly reduced scale showing the sanding disk when the same has been pressed down into full operative position and slowed down as a result, and showing by the shaded area the much larger area contacted by the active surface of the sanding edger disk.

Fig. 10 is a full size sectional view of one form of sanding edger disk.

Fig. 11 is a longitudinal sectional elevation of the forward part of the machine below the base plate showing the position of the sanding edger disk when it first contacts the floor when the disk is not running and also showing two layers of fabric running through the disk near its bottom.

Fig. 12 is a side elevation view of the forward part of the machine showing the disk when running at high speed as its forward edge has made partial contact with the floor surface, as shown in Fig. '7.

Fig. 13 is a view similar to Fig. 9, showing the position of the disk while full sanding operation is going on with the maximum area of the disk in contact with the floor, as indicated in Fig. 8.

Fig. 14 is a transverse sectional elevation view taken on line l4l4 of Fig. 1 and Fig. 7.

As shown, a base member I2 is provided with an outer depending flange l3 and an inner depending flange Id, Figs. 2 and 5. The flange I3 has a front portion at each side, designated respectively as 55 and I6, that is united to a transverse part H, which has its edge cut away, as clearly shown at [8 and [9 in Figs. 2 and 4. The inner flange I 4 has forwardly extended legs 20 and 2!, which meet extensions 22 and 23 of the outer flange portions [5 and I6. The sanding disk, later to be described, therefore, rotates below the bottom edges of flange portions 20 and 2| and in a forward recess 24, Fig. 6, between the joined ends of outer flange portions l5 and I6 and inner flange portions 26 and 2|, as best shown in Fi 6.

A plate 25, Fig. 2, is secured throughout its extent upon the bottom edges of flange members [4, 2i], 2| and I1, and it is secured in air-tight relation to the bottom of said flange members by screws 26. This bottom plate provides a sealed chamber 27 and in this chamber is a V-belt pulley 28 on a vertical motor shaft 29. Pulley 28 has thereon a V-belt 30 which extends about a large V-pulley 3| having a hub 32 which is removably held upon a roller bearing 33 by means of a plate 34 held upon hub 32 by screws 35. The hub 32 is adapted to have removably secured thereto one of a number of different forms of edger sanding disks 36, as clearly shown in Figs, 2, 10, 11 and 14.

A highly important feature of myinvention is found in the edger sander disk which isemployed in my new sanding edger, and in its means of support and operation. The characteristics of the sander disk are well shown in. the sectional views through the same appearingin Figs. 2, 10, 11 and I l.

In all of these different forms the sander disk comprises a body portion of' rubber, and reinforcing nonstretchable layers of material vulcanized into said body portion.

In the form of the invention of: Fig. 2 the rubber body is designated as 31. In the form of the invention of Fig. 10 the; body portion is designated as 44. and in the: form of the. invention of Figs. 11 and 14 the body portion is designated as 53. The disks or padsthemselves, therefore, in this specification will be referred to hereinafter as 31, 44 and 53.

Each of these disks comprises acentral portion 45 with a cutaway or socket part 40 for a use hereinafter defined. The. central portion in each case is formed with screw openings 46 and 41 for securing the disks 31, 44 or 53 to the plate 34 by means of screws 4| which go through the openings 46 and 41 and thread into the piece 34, and which, as heretofore noted, is in turn secured by screws 35 to the. pulley hub 32. Although this is one form of securing these parts together which may be practically employed, we may directly bond the plate 34 to the rubber pad in any of its forms.

In the forms of the invention here shown the body of the disks 31, 44 or 53. dishes or is con cave toward the floor surface which is to be engaged by the disk. But I do not wish to be limited to a disk structure which is concave toward the floor, since the principlesof my invention may be employed with a. disk which is convex toward the floor and, under: some working conditions it may be desirablev to employ such a disk, although, as stated, the dished form concave toward the floor is the preferable form.

The recess or socket 411 in the under side of the central portion 45 of the disk body, whichever form is employed, is adapted to receive the broad head on the threaded bolt 43 which passes through the opening 48, having fiaringwalls 49, Fig. 6, and which holds upon the face. of the disk opposed to the surface of the fioora suit able disk of sandpaper 42, thus replaceably secured to the outer face of the sanding disk or pad. This sandpaper disk 42- will, of course, be held firmly in contact with the floor surface between it and the lower, surface of the sanding pad during operation of the machine.

The several disks 31, 44 and. 53 differ from each other primarily in the distribution of nonstretchable material imbedded in thexrubber of the disk. This material will preferablybecertain types of fabric, such as forms of canvas, which resist stretching in all directions.

In each case as best shown in Figs- 10, 11 and 14, .the fabric itself must extend into the central portion 45 of the disk above the; socket 4! so that stretching outwardly of the disk when in rotation at high speed will be effectively resisted. In the disk 31 of Fig. 21the; introduction of the nonstretchable-material isyatboth: the. top and the bottom of the body of. the disk as: indicated at 35 and 3 9.

Inthe form of disk 44, shownzin Fig: 1 theanonr stretching; material is positioned. in. the upp part of the body of disk 44, as indicated at 51 and 52. In the form of disk shown in Figs. 11 and 14, which may be regarded for many purposes as the preferred form, the nonstretchable material is positioned in the bottom portion of the disk, as indicated at 54 and 55, and, of course, so positioned it has to overlie at its ends outer parts of the socket 40.

These three edger sanding disks, 31, 44 and 53, therefore differ only in the distribution of reinforcing material in the respective disk bodies. This difference in positioning the material has an effect upon the manner in which the disk responds to the application thereto of centrifugal force during rapid rotation thereof, but can besatisfactorily employed in any of the designated positions.

As shown in Fig. 4, the bottom frame member flanges l3 and M- on base member 12 are spaced apart so as to leave a horseshoe-shaped rear channel 54. Between them are forward side channels 55 and 5% which extend around the forward parts of the flanges to the front end plate I'i.

These channels or passageways extend downwardly into a chamber 5'! which extends across the bottom casting between the flanges l5 and i6, as shown in Fig. 5.

The broad passageway El is open to the floor when the machine is in operation and extends forwardly to the sander disk 31 in position to receive directly the sander, dust removed from the floor and from the sanding paper. chamber 5? opens directly to passageways 58 and 59, Fig. 5, extending upwardly between flanges 2c and 2! on the inside and flanges l5 and [6 on the outer side and discharges through port openings iii! and 6! through the top plate l2, and motor base l2 thereon.

As best shown in Fig. 5, the ports 60 and GI open into a passageway 62 in a housing 63,.Fi'g. 2, secured to the motor casing, which passageway leads to a blower chamber 54,

A blower 65 operates in blower chamber 64 and draws dust-laden air from off of the floor back of the sander disk 37 and from chamber 57. This dust goes through passageways 58-6ll and 59-5! and into and through passageway 62 into the blower 85, from which it is forced through passageway 65 in connecting pipe 61 into the dust collecting bag 58.

In order to distribute the dust-laden air more effectively to passages 651 and 6!, I provide a divided bafiie comprising a shorter plate 69 and a longer plate it, Fig. 3. These plates meet at a point ll and guide the dust-laden air from chamber 5? to the respective passageways through the top plates :2 and '12 and into the exhaust passageway The arrangement of the divided bafile is such as to equalize the carrying of dustdaden air from the chamber through the two openings 69 and 5! to the discharge pipe G2. The shorter baffle plate 69 catches perhaps a larger part of the heavy throwoff of dust from the sander disk, while the longer bafiie plate Iii gathers up the flow from the succeeding longer arc of the sander disk.

This arrangement provides a peculiarly effective means of withdrawing all dust generated by the sanding disk 3? immediately on" of the floor, and of transferring it to the dust-collecting bag,

since air will be caused to move along the floortoward the openingstll and BI as the dust-is" thrown off from the sanding disk, and no dust is The.

permitt'ed'to settle or to go otherwise than to the dust collecting bag 68.

-In this connection it will be noted that the bearings 33 for the sander disk, pulleys 23 and 3!, and belt 32, are all mounted to operate in the sealed chamber 21. For, although the plate 25 is subject to removal by simply withdrawing screws 26, it is not often removed after the parts are installed and is secured to make the chamber 2'! air and dust tight. The belt 30 may become slack and require tightening from time to time. To accomplish this without removing the plate 25 the following means are provided.

A motor base I2 is slidably rested upon the top of base member I2, as best indicated in Figs. 2 and 4. Motor shaft 29 extends through the motor base I2 and through a slot 13 in top base plate I2. Other parallel slots 14, I5 and I6 in top plate I2 are formed with reinforcing rings 11, I8 and I5 about them. Through the slots I I, I5 and I5 extend strong screw bolts 80 provided with washers 8|, Fig. 2, for engaging the reinforcing rims I1, I 3 and '59. These bolts are threaded through the motor base I2 and into a heavy supporting rim 82 thereon, as shown in Fig. 2.

Hence, to tighten the belt it is only necessary to release the screw bolts 80 extending through the slots 14, I5 and IS and to push the motor base I2 and the parts carried thereby rearwardly enough to sufiiciently tighten the belt 30, after which the bolts may be reset.

The motor casing 83 is sealed air-tight at its bottom to the motor base I2, and is formed integral with the top 84 of the motor chamber. Hence the motor chamber 85 is itself sealed airtight from the dust stream going through the passageway 62 formed by the housing member 63, which is integrally united by casting or otherwise with the motor casing wall 83.

The casing wall 83 is subject to the cooling effect of the stream of dust-laden air in passageway 62 that moves along the motor casing wall 83 and above the topwall 84, which tends to cool the motor chamber 85.

This chamber is additionally cooled by air drawn through openings 86 in the member 62 and caused to move through and be discharged from motor chamber 85 by a fan 81. The air passes out of motor chamber 85 through slots as that extend through wall 83, as shown in Figs. 2 and 6.

It will be noted that the fan 81 is mounted on the motor shaft 29 below the motor. Further that the blower 05 is mounted on an extension 89 of the motor shaft above the motor as shown in Fig. 2. The motor bearings 90 and 9|, therefore, and the motor chamber 85 itself are thus completely protected from entrance of any of the sander dust.

Thus the motor chamber is effectively cooled both by contact with part of its wall 83 with passageway 62, and by the air forced through the motor chamber by blower 81.

The rear handle 92 of the sander edger is hollow having a passageway through it as indicated at 93 and the passageway 93 expands to a chamber 94 within a casing member 95. The chamber 94 communicates through an opening 96 with the motor chamber 85 and provides a housing for switch means 91 and timing means 98, shown diagrammatically in Fig. 2. The handle 92 is thus aerated and cooled by the air driven through the motor chamber 85, which pulls air through the opening 96 and slits 96 in the handle body, and about plug I00.

' Electric current is delivered through a cord 99, which is connected with plug I00 in the outer end of the handle. The cord is connected at its other end with a contact plug IOI, Fig. 2.

To the forward extension of base plate I2 is secured a hand knob I02. The handle 92 is rigidly attached, and in the practice of using the sander edger one hand of the operator grasps the handle 92 while the palm of the other hand engages the knob I02 with a degree of force sufficient to hold the sanding disk in firm engagement with the floor. However this engagement with the floor is held down to a minimum which will prevent any scoring of the floor or overloading of the motor, and which is brought about by the following means:

Extensions I03 and I04 on opposite sides of flanges I5 and I6 are clearly shown in edge elevation and in plan in Figs. 1 and 6, and are shown in an under plan view in Figs. 4 and 5. These extensions I03 and I04 form chambers I95 and I05 within each of which is bolted a crossbar IEi'I, clearly shown in Fig. 5. Independent trunnion arms I08 and I09 support a transverse shaft III] extending across the'width of the margin and upon each and over which is mounted rollers I I I and II2 within each of said chambers I05 and I55, and which rollers extend downwardly through the open bottoms of said chambers to contact the floor.

The entire base frame under the base plate I2, and the parts carried thereby is given rocking support in a transverse plane on rollers I II and H2, which are quite widely spaced (see Fig. 4), with broad bearing surfaces, thus holding the sanding edger to rock about a substantially horizontal axis and insuring presentation of the sanding disk to the floor so as to effect action thereof on the surface of the floor in a plane tipped upwardly from its plane of rotation perpendicular to the'sanding disk. The operator with his hand on the knob I02 exercises pressure which is transmitted to the outer limits of the edger sanding disk. However, since this is a flexible member and centrifugal force tends to force it into a plane perpendicular to its axis of rotation, the actual pressure upon the part of the disk which engages the floor is in fact caused by centrifugal action upon a body of the pad and of the sandpaper disk carried thereby.

This action is well shown in Figs. 7, 8, 9, 11, 12 and 13. As shown in Figs. 7, 11, 12 and 13, the lower edges of the outer flange extensions I5 and I0 are bevelled or sloped upwardly from points II3 a short distance in front of the axis of wheel supports III and H2. The rear bevelled edge II4 extends back to the lower edge II5 0f the rear extension I3 of the entire flange member while the front portion I I 6 extends forward- 1y in such relation to the transverse axial support on rollers III and H2 that when the front part H1 is rocked upon the axis of the rollers to the maximum extent possible, the edges IIB of the flange member front portions I5 and I6 will engage the floor through its extensions as indicated at 'IIS and H9, see Fig. 4. This, of course, will be where the bottom portions I20 and I2I of the transverse member also engage the floor.

It follows that no matter how great a pressure the operator may put upon the knob I02, that pressure can not be transmitted to the sanding disk in operation, beyond the amount, as indicated in Fig. '7, where the edge I I6 of members I6 and I6 engages with the top surface I22 of the "noon This maximum pressure upon the sand- "Ing disk, :as so. .limited, can never be sufficient .ertherto cause the sanding disk to score the floor turned on. In other words this is the position of the sanding disk when stationary and atwhich "time its forward edge at I23 either is rotating entirely free of or so it just touches the floor.

The position of the parts shown in Fig. 12 is taken after the power has been turned'on and the sanding disk is rotated at high speed but not under any pressure, or with very little pressure, from the knob I02. In this position, as indicated also diagrammatically in Fig. 6, centrifugal force has brought the dished sanding disk 53 into a position in which its surfaces are rotating in substantially a plane perpendicular to the axis of rotation and the floor is contacted by a small part of the face of the disk, indicated at I24 in Fig. 12, and by the shaded area also designated as I24 in Fig. 8.

In this position friction will have slowed somewhat the rotation of the sanding drum 53 over the initial speed and the sanding operation will have very lightly begun.

In Fig. 13 the sanding operation is illustrated in its normal full sanding speed. Here, pressure has been applied to the knob I92, which has resulted in considerably slowing the rate or rotation of the sanding disk 53. The lower surface edges of the frame are still spaced from the surface of the floor, as indicated at I26, and an area I of the sanding disk is engaging the floor with a proper degree of pressure, as indicated by the lines I25 in Fig. 13 and the shaded area also indicated as I25 in Fig. 9.

When in this position the front edge I21 of the sanding disk will project to the line of junction between the lower edge of the molding and the surface of the floor when the sanding edger is experienced or careless, so excessive pressure is put on the knob, it can not and will not unfavorably affect the sanding operation, for all excess pressure will be exerted against the edges H6, I20 and I2I of the flange members I and I6.

Indeed, in the position of either Fig. 7 or Fig. 13, the actual sanding pressure against the floor will be exerted principally by the centrifugal action upon the whirling sanding disk, which tends to straighten the disk and its surfaces into planes extending at right angles to the axis of rotation of the disk indicated at I28, as clearly shown in Figs. 7 and 13.

It follows that not only is the edger sanding operation of this machine independent of lack of experience or carelessness of an operator using the machine, but at all times the pressure exerted upon the floor surface is effected not by a direct pressure thrust, but by the uniform and steady centrifugal floor contacting action of the sanding disk upon the floor surface.

This is the principal and highly important advantage of my invention, since it assures a perfect edger sanding operation flush against the baseboard molding without possibility of injury to the floor or overloading injury to the motor, no matter how inexperienced or careless an operator using the sanding edger may be.

A second principal and highly important advantage of my sanding edger resides in the sanding disk itself. This dished disk of rubber with the reinforcing nonstretchable material in the body-of the rubber is in itself a highly advantageous feature of my invention, which makes'possible the arrangement of the disk on the bottom frame, whereby the forward-edge of the disk is bent out of the plane perpendicular to the axis of rotation of the disk, and that rotation at high speed tends to bring the bent part of the disk into that plane, and produces the principal force exerted by the part of the disk against and which contacts the surface of the floor.

Another highly important advantage of the edger comes from the fact that the dust conveying mechanism not only certainly and effectively removes all dust generated by the action of the sanding disk, but that all moving parts excepting the disk itself, including all bearings, are mounted and housed in such manner that sander dust can not get to them at all.

Another highly important advantage of the invention is that all the driven parts of the machine are operated directly from a single motor shaft with no intervening gearing, with only the direct drive by belt and pulley from the motor shaft itself to the sanding disk, this drive always being along a right line plane normal to the axis of the motor shaft and to the axis of the sanding disk.

Another highly important advantage of my invention resides in the arrangement of passages and the movement of the dust-laden air to the dust cooling bag, whereby some of the heat generated by the motor is withdrawn from the motor chamber, together with the establishment of direct currents of air through the motor chamber and over all parts of the motor to discharge outside the motor casing, thus effecting unusually satisfactory cooling of the motor brought about with small consumption of power.

Other advantages of my invention are found in the compactness, sturdiness, and economy of manufacture of my sanding edger, its relatively light weight, and its small electric power consumption as related to its high efiiciency and large capacity.

I claim:

1. A floor sanding edger, comprising a, bottom frame having downwardly depending flanges forming an open-bottomed chamber including forward and rear portions, a flexible sanding disk within the forward portion of the chamber rotatably mounted on the frame, a motor on the frame for rotating the sanding disk, and a trans verse support for the frame normally holding the flanges out of contact with the work surface, said flanges sloping upwardly from points forward of the support in a plane at an angle to the normal plane of the sanding disk, such that said sloping plane intersects the forward part only of the sanding disk, whereby when in op- 7 only by the bending of the flexible sanding disk and centrifugal force tending to straighten said bending.

2. A sanding edger, comprising a base frame, a sanding disk mounted in the frame and positioned at the bottom of its front end, a motor 7 casing on the frame, a vertically supported mo- 12 and a blower in the casing on the shaft below the motor for drawing outside air into and discharging it from all said openings including the open ing into the hollow handle.

WILLIAM P. HILGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 21,180 Myers Aug. 22, 1939 1,650,035 Peterson Nov. 22, 1927 1,725,361 Mall Aug. 20, 1929 1,779,682 Stratford Oct. 28, 1930 2,172,407 Ramey Sept. 12, 1939 2,227,588 Kemp Jan. 7, 1941 2,242,229 Burleigh May 20, 1941 2,251,442 Emmons Aug. 5, 1941 2,281,722 Smith May 5, 1942 

